Electrochromic Semiconductors as Colorimetric SERS Substrates with High Reproducibility and Renewability

Electrochromic technology
has been actively researched for displays, adjustable mirrors, smart windows,
and other cutting-edge applications. However, it has never been proposed to
overcome the critical problems in the field of surface-enhanced Raman scattering
(SERS). Herein, we demonstrate a generic electrochromic strategy for ensuring
the reproducibility and renewability of SERS substrates, which are both
scientifically and technically important due to the great need for quantitative
analysis, standardized production and low cost in SERS. This color-changing
strategy is based on a unique quantitative relationship between the SERS signal
amplification and the coloration degree within a certain range, in which the
SERS activity of the substrate can be effectively inferred by judging the
degree of color change. Our results may
provide a first step toward the rational
design of electrochromic SERS substrates with a high
sensitivity, reproducibility, and renewability.